A preliminary study of wheat genetic diversity in the People's Republic of China is presented. Available evidence and basic data related to the ancestry of leading wheat cultivars and the area distribution of dominant ...

The importance of rice-wheat cropping systems in meeting present and future food needs in South Asia is reviewed. Evidence from a number of factor productivity studies, which analyze yield trends after adjusting for changes ...

Results from a study of maize varieties and seed sources in a traditional community in Mexico raise questions about the relevance of models for in situ conservation of crop genetic resources that are based on geographical ...

This paper focuses on intensifying maize-based cropping systems in the Sierra de Santa Marta Region of Veracruz, Mexico. Following a description of the study area, the paper examines the historical forces that have shaped ...

This study explores factors associated with farmers' decision to experiment with velvetbean (Mucuna spp.), a green manure, as a maize intercrop in three villages of Veracruz, Mexico. To asses whether velvetbean might be ...

Factors related to the low use of fertilizers and the resulting low agricultural productivity in sub-Saharan Africa are reviewed. The importance of inorganic fertilizers and agricultural research to improving soil fertility ...

This paper examines the implications of declining soil fertility for the maize-based cropping systems in southern and eastern Africa. A review of the importance of maize in the region is followed by a description of the ...